If the DNA template strand is: ATG CTC CTT GGT CTT TCT GCA AGT GCT it can be copied to an mRNA in a process called transcription. The base pairing rules are basically the same as those in DNA replication with one exception. If there is a thymine on the DNA, the complementary base on RNA is adenine. If there is a cytosine on the DNA, the complementary base on the RNA is guanine. If there is a guanine on the DNA, the complementary base on RNA is cytosine. If there is an adenine on the DNA, the complementary base on RNA is uracil because RNA lacks the base thymine and uracil will pair with adenine in this case.

Taking into account each codon or triplet in the DNA in your example, the mRNA transcript will read: UAC, GAG, GAA, CCA, GAA, AGA, CGU, UCA, CGA. This messenger RNA will next be edited and sent out to the cytoplasm where its genetic code can be assembled into a polypeptide at the ribosomes during protein synthesis in a process known as translation.